RESUMO
2 congenic strains of mice, B6N.AKN-Ahk and D2N.B6N-Ahb, imported from the USA, were found to be either segregating or fixed for an incorrect allele at a number of biochemical loci. B6N.AKN-Ahk, supposedly congenic with C57BL/6N, had the wrong genotype at 6 out of 12 biochemical loci; D2N.B6N-Ahb, supposedly congenic with DBA/2N, was segregating at 3 out of 9 loci. There was genetic variation in mandible shape within the 2 strains but no abnormal coat colours were found and no hybrid vigour in breeding performance was detected. Analyses in the USA confirmed these results and showed that 2 other congenic strains, C3N.D2N-Ahd and AKN.B6J-Ahb, were also segregating at a number of loci. Some of the alleles found in the C3N.D2N-Ahd mice must be the result of a genetic contamination. The simplest explanation for this breakdown in the backcrossing programme is genetic contamination with other congenic strains or recombinant inbred lines under development in the same laboratory. These findings emphasize the importance of continual genetic monitoring of all genetic stocks at regular intervals and in particular during the development of congenic and recombinant lines.
Assuntos
Variação Genética , Camundongos Endogâmicos/genética , Alelos , Animais , Animais de Laboratório , Cruzamentos Genéticos , Feminino , Marcadores Genéticos , Heterozigoto , Masculino , Mandíbula/anatomia & histologia , Camundongos , Camundongos Endogâmicos/anatomia & histologia , Camundongos Endogâmicos/fisiologia , ReproduçãoRESUMO
Strain-specific polyvalent alloantisera may be obtained by injecting lymphocytes pooled from several different strains into an inbred recipient. 6 sera of this type were produced in rats and 23 in mice. A dye-exclusion microcytotoxic test was used to evaluate the strain specificity of such sera. A total of 663 out of 713 (93.0%) of the tests conformed with expectation, but there were 58 (6.7%) false negative results in which the test failed to detect non-authentic animals. There were also 2 (0.3%) false positive results, in which authentic animals were shown as non-authentic. These were attributed to technical errors. Most false negative results occurred when serum and test cell suspensions matched at the major histocompatibility complex. It was concluded that the use of strain-specific polyvalent immune sera, coupled with a simple immunological test such as the microcytotoxic test, offers a sensitive and quick new method for routine genetic quality control.
